Eating more when you're sleep-deprived is not a new concept, but the answer to why this is the case just got a lot more interesting. You might have heard that being sleep-deprived (having five hours of sleep or less) disrupts our circadian rhythm or that sleep affects our hunger hormones, but this new reason takes the concept to a whole new understanding.

Apparently a lack of sleep correlates to an increase of endocannabinoid, a lipid found in the bloodstream. This compound seems to affect the same part of the brain as cannabis. That's right: When you're sleep-deprived, you basically have the munchies — food is simply more appealing

In a new sleep study conducted by the University of Chicago Medical Center, they used 14 participants to see how sleep affected their eating habits. The participants only slept four-and-a-half hours a night for four days, and they were given buffet meals and way too many snacks. They apparently ate more than 400 extra calories from snacks.